It's just a picture I swiped from the internet to illustrate a point, but it has happened to a friend of mine.
There is a great photo of a Lotus 12 or 16 with a twisted shaft . I think it is in the "Theme Lotus " book tracing the history of Lotus Formula 1
The original shafts (tubes) are small in diameter. I had a replacement made more than 25 years and they couldn't source tube that small. The replacement felt twice as heavy, suggesting the wall thickness of the originals was "light". Lotus wouldn't have it any other way!
A small increase in diameter gives a large increase in torsional stiffness. The stiffness increases to the power of 4 v's radius.
I first saw twisted prop shafts like these when I worked at Kenworth trucks. More recently there has been a spate of prop shaft failures on our local rear drive Holdens and Ford Falcons. With 300kw off the show room floor, and heaps of additional power available with a few tweaks, prop shafts have become the weak link. Our drive shafts take a lot of torque (the diff and gearbox is a torque multiplier) so drive shaft failure and U/J will occur with high horse power.
Our historic race cars do standing starts, and there is nothing like a day of 1/4 mile drags to give your rear end a good work out!
A few years ago I went to a country drag meeting. they had two categories. Below 10 seconds and above. I chose the later.
Pretty sure I was slowest time of the day at around 14.5 seconds
